Race to get comet data before Philae dies

Barely 24 hours have passed since the European Space Agency’s Philae spacecraft made history as the first probe to touch down on a comet. Now ESA researchers are racing to gather the maximum amount of scientific data from comet 67P/Churyumov-Gerasimenko before Philae shuts down and they lose contact for good.

This morning we learned that Philae bounced twice before settling down in an unknown location on the comet, perhaps a kilometre away from its original landing spot. Two of its legs are on the ground, but the third is up in the air, putting Philae at an angle. It is also sitting in the shadow of a rocky wall, limiting the sunlight that can reach its solar panels to just 90 minutes every 12 hours.

Philae’s batteries will run out in less than two days unless recharged, and it is unlikely the solar power it is receiving will keep it alive. “We are calculating now what this means for the near future,” said lander manager Koen Geurts during a press conference this afternoon. “This is not a situation we were hoping for.”

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Eight of the ten instruments aboard Philae have already sent back scientific data, and ESA already considers the mission a huge success. Senior mission staff were moved to tears of joy during today’s press conference.

(Image&colon; ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

But efforts to squeeze as much data as possible from the mission are still under way here at the European Space Operations Centre in Darmstadt, Germany. Holger Sierks, who is charge of the OSIRIS camera on Rosetta, has two teams desperately scanning images by eye for Philae’s final landing spot. The lander occupies just a 3 by 3 grid of pixels in the OSIRIS images, so this really is searching for a needle in a comet.

“We’re working our eyes off,” Sierks told New Scientist. It’s an entirely manual process, because the complex and bizarre landscape of comet 67P defies any kind of automated search. “We don’t have an algorithm for this,” he says.

Finding the lander in a picture will help the Philae team determine its surroundings, figure out what kind of illumination it is getting and thus how much power they can expect to receive from the solar panels.

ESA is also considering attempting to move Philae to a more favourable spot, but with no propulsion system on board this is a risky and untested plan. Philae has four instruments and systems that involve motion, and each has the potential to move the probe, so its solar panels get more light. “If we can move a few degrees it might be sufficient,” Philae scientist Jean-Pierre Bibring told New Scientist.

They are planning to deploy the instruments in order of increasing risk, starting with a probe called MUPUS this evening. MUPUS has a small hammer, and the up and down motion could give Philae the jolt it needs. The craft’s harpoon, drill and cold gas thruster could also be repurposed into a makeshift crutch to drag, push or boost Philae into the light.

Senior ESA staff have already worked through the night to determine Philae’s status, and they continue to meet every 2 hours to decide the best course of action.

Whatever happens, the instruments on board the spacecraft will give us the first ever up-close look at a comet, perhaps revealing mysteries about the origin of Earth and the water and other molecules that gave it life.

But hopes that Philae will survive until March next year, when it would finally succumb to increasing heat from the sun, are fading fast, meaning ESA may not get a chance to touch and taste the comet as it heats up. “The long-term science is most at risk,” says Bibring.